Owing to various novel properties of nanoparticles, (see, for example, R. W. Siegel, E. Hu, and M. Roco (eds.), Nanostructure Science and Technology 1999) it is of increasing interest to use them as building blocks for well-defined structures that have practical applications. However, their assembly is a challenging task. Methods based on surface functionalization, and/or template patterning have been used for this purpose, but both of these processes can be rather complicated. Therefore, there is a continuing need for a simple method for synthesizing high aspect ratio microstructures constituted of nanoparticle building blocks.